Process of recovering volatile organic acids from distillery waste



L. M. BURGHART. I PROCESS OF RECOVERING VOLATILE ORGAN l0 ACIDS FROM DISTILLERY WASTE.

APPLICATION FILED JUNE 24, I918.

Patented Aug. 22, 192-21..

UNHTED STATES OFFICE.

LLOYD M. BURGHART, OF GOVANS, MARYLAND, ASSIGNOR TO U. S. INDUSTRIAL ALCOHOL (10., A CORPORATION OF WEST VIRGINIA.

Specification of Letters Patent.

Patented Aug. 22, 1922.

Application filed June 24, 1918. Serial No. 241,502.

To all whom it may concern:

' Be it known that I, LLOYD M. BURGHART, of Gov'ans, in the county of Baltimore, and in the State of Maryland, have invented. a certain new and usefu Improvement in Processes of Recovering Volatile Organic Acids from Distillery Waste, and do hereby declare thatthe following is a full, clear, and exact description thereof.

My invention relates particularly to a process for treating the waste obtained from distilleries in the production of alcohol.

The object of my invention is particularly to utilize the waste obtained from the distillation of various materials used in the production of ethyl alcohol.

More particularly, the object of my invention is to make use of the waste materials obtained in the production of ethyl alcohol from sugary materials such as molasses, which may, for example, be; obtained in the manufacture of cane or beet sugar, or from potatoes, or grain, such as wheat, rye, barley, corn, etc.

The object of my invention is, furthermore, .to provide a process by means of which the esters of volatile organic acids,

and particularly of the volatile acids of the aliphatic series, may be readily obtained andwithout the application of high temperatures in the distillation thereof, as hereinafter referred to.

Further objects of my invention will appear from the detailed description thereof contained hereinafter.

While my invention is capable of being carried out-in many different ways, for the purpose of illustration I shall describe only one way of carrying out the same herein; and while my invention is capable of Using carried out in connection with many difl'erent types of apparatus, 1 shall describe only one type of apparatus which may be used in connection therewith in the accompanying drawings, in which- Figure 1 is a diagrammatic representation .of an apparatus which may be used in connection with my invention; and

Figure 2 is an end elevation of a type of car, used in connection with the same.

In the drawings, I have shown two preliminary mixingtanks 1, having a plurality of stirrer arms 2, adapted to be rotated in any suitable manner, said tanks 1 being prothe same, which trucks may be arranged to runupon a track 7 into a furnace chamber 8. The material in the pans 3 becomes dried in this manner to form a clinker. This clinker cohtains sodium oxalate, as well as sodium salts of a number of volatile acids, such as formic, acetic, butyric acids, etc. The clinker maybe then removed from the pans and introduced into a plurality of wooden tanks 9. These tanks 9 may besupplied with a quantity of water and sulphuric acid, and the "contents of, said tanks may be heated by means of live steam fed into the same by means of a pipe 10, having branch pipes 11, leading into the same. Said steam pipes 11 may have a pipe 12 connected thereto to supply compressed air, in order to assist in the agitation of the materials contained in the tanks. The sulphuric acid is added to neutralize the excess alkali, as neutralization is found to aid in the subsequent filtration. Thereafter a quantity of lime is added sunicient to precipitate the oxalic acid as calcium oxalate. The liquids may be then transferred from the tanks 9 to a filter 13. The filtrate from the filter 13, which contains the sodium salts of the volatile acids above referred to, may be evaporated to dryness, or nearly so, and may be then treated in a still 14:, which may have a heating jacket 15, an inlet for live steam 15 and a refluxing column 16 with a nonvolatile mineral acid such assulphuric acid in excess of that required to liberate the volatile acids and with a quantity of methyl alcohol, said still preferably having a vapor outlet pipe 17, leading to-a condenser 18, which may be provided with an outlet pipe 19, leading to a receiving tank 20, connected by pipe 21 to a vacuum pump 22. In the employment of the foregoing apparatus the crude esters of the volatile acids collect in the tank 20 and may be. drawn ofli therefrom by a pipe. 23 and conveyed by the same to a column still 24, which may have an inlet 24! for live steam and a vapor outlet pipe 25 leading to a con denser 26. From the condenser 26, the esters by weight of caustic soda in the tanks 2, until the alkali has become completely dissolved. llf desired,-the two tanks 2 may be operated alternately, so that, while one tank is being charged, the other is being dis charged. The mixture thus obtained may be transferred to the pans 3 on the trucks 4 and is introduced into the furnace chamber 8, where the material may be subjected to a temperature of from 175 to 250 C. for 8 k to 24 hours, the time of treatment bein vaperature is higher.

ried according to the temperature. here the temperature is low, the treatment is for.

a longer period of time than where the tem- When the reaction is complete,the treatment in the furnace chamber 8 is discontinued. The efiect of thetreatment in the furnace chamber 8 is principally to bring about the production of volatile organic acids as well as oxalic acid. The clinker thus obtained, and which contains a quantit of sodium oxalate amounting to approximately 10% of the Weight of the clinker, and a quantity of sodium salts of a number of volatile acids, such as formic, acetic, butyric acids, etc, amounting to. from 12% to 20%. of the weight of the clinker, may be treated with, for example sulphuric acid in the proportions of one part by weight of clinker, two parts by weight of Water, and one-third part by weight of sulphuric acid of 66 Be. in the tanks 9. The amount of sulphuric acid that is intended to be used is sufficient merely to neutralize the alkali and not to liberate the oxalic acid and volatile acids pressed air through the pipe 12, if desired.

Then a suificient, quantity of lime, or the like,

may be added to precipitate the oxalic acid as calcium oxalate. The amount of lime added will usually'be about 5% of the weight of the clinker introduced into the tanks 9.

The calcium oxalate and other solid materials present are then separated from the liquids by means of the filter 13. The filtrate from this filter will contain the sodium salts of the volatile acids above referred to;

i The filtrate may be then evaporated to dryness, or nearly so. The solid materials are then'introduced into the still 14k, and a quantity of the same, amounting to 2002;}

insane? pounds, is treated therein with 80. pounds of concentrated sulphuric acid of 66 Be. and 50 pounds of methyl alcohol.' Instead of the methyl alcohol, however, ethyl or amyl alcohol may be used, but I prefer to use methyl alcohol, as thereby the temperatures of distillation used in distilling the esters of the volatile organic acids may be kept at a very low point. The/materials in the still 14 may be then heated forsome 3 hours, while using the refluxing column 16, at a temperature of for example 20-25 G., and thereafter the methyl esters of the volatile or anic acids may be allowed to distill over't rough the tube 17, after which they may be cdndensed in the condenser 18 and receivedin the tank 20. From this oint the methyl esters may be withdrawn or any desired purpose or may be purified and se aratedby treatment in the column still 24, from which the products produced may be condensed in the, condenser 26 and received in the receiving tanks 27, 2e, 2e.

In this way the methyl esters; of formic, acetic and butyric acids may be obtained, and thereafter, if desired, the formic, acetic and butyric acids may be obtained in any desired manner, as for example by treating each of the methyl esters by addin thereto an excess of caustic alkali to saponlfy the same, distilling 0d the methyl alcohol, evaporating to recover .the dry salt, treatin with an excess dill of concentrated sulphuric acid to liberate the corresponding acid and recovering the latter by distillation. 1

While I have described my invention above in detail, ll wish it to beunderstood that many changes may be made therein Without de arting from the spirit of my invention. or example, instead of calcium compounds, ll'may usesalts of the other alkaline earth metals, and l wishthis to be understood Wherever T have referred'to the use of calcium compounds; and instead of canstic soda, ll may use other alkalies or carbon ates of the alkali metals or mixtures oi? the same.

ll claim: A

1. The process which comprises mixing a soluble caustic with a quantity of sugary materials, exposing the mixture to heat suihcie'nt to form a clinker comprising a corresponding soluble oxalate, dissolving the thereafter treating it with an excess of a non-volatile mineral acid; and with an alcohol while collecting the esters evolved therefrom under reduced pressune.

2.. The process. which comprises EN: ring a solubleraustic with a quantity. of sugary meterials, exposing the mixture to furnace heat suflicient to form a clinker comprising a corresponding soluble oxalate, dlssolving this oxalate and associated salts in acidified water, separating solids from the solution so formed, thereafter adding to the filtrate lime sufficient to precipitate calcium oxalate, separating the precipitate from the liquid portion, evaporating the liquid portion, and

thereafter treating it with an excess of anon- 10 volatile mineral acid and with an alcohol while collecting the esters evolved therefrom.

In testimony that I claim the foregoing I have hereunto set m hand.

LLO D M. BURGHART. WitnTesses :P G

OHN 180mm,- ARTHUR WRIGHT. 

